Lawn-grass professionals divide the United States into four main zones of grass adaptation based on climatic conditions. The Northeast region of the country falls into what's known as the cool, humid zone. Lawn grasses that do best in the Northeast are hardy, cool-season grasses that tolerate humidity in addition to cold.
Because most lawns have areas that vary in moisture as well as sun and shade exposure, a mixture of cool-season grasses normally delivers the best overall lawn. Using a mixture allows different, complementary grass types to dominate in various areas and conditions that fit them best. The major perennial lawn grasses that flourish in cool, humid Northeast conditions are:
- Kentucky bluegrass (Poa pratensis), which is hardy in U.S. Department of Agriculture plant hardiness zones 2 through 6. Although slow to establish from seed, Kentucky bluegrass spreads vigorously via underground stems known as rhizomes once it gets settled into sunny lawns. That spreading behavior also helps it repair itself when damaged by foot traffic or other injuries. Known for its green color and fine texture, Kentucky bluegrass flourishes in cool temperatures with the consistent soil moisture common in Northeast lawns.
- Perennial ryegrass (Lolium perenne, USDA zones 3 through 6), which establishes quickly and greens up fast in spring, making it a welcome complement to Kentucky bluegrass. Some perennial ryegrass varieties have improved longevity over older, traditional varieties and offer a finer texture that mixes well with other cool-season grasses. This versatile lawn grass tolerates sun exposure, some shade and adapts well to changing Northeast conditions, but it does not tolerate overly wet soil.
Tall fescue (Festuca arundinacea, USDA zones 4 through 7), once considered only forage pasture grass but recognized by
turf breeders for its potential as a resilient lawn grass. Fairly new varieties known as turf-type fescues retain tall fescue's clumping growth habit and its ability to thrive in poor, droughty soil. Deep-rooted, turf-type tall fescues stand up well to foot traffic and bring Northeast lawns improved texture, color and drought tolerance.
- Fine fescues (Festuca spp.), such as creeping red fescue (Festuca rubra var. rubra, USDA zones 3 through 7). They excel in well-drained shade and dry areas that challenge other Northeast lawn grasses. Although these low-maintenance lawn grasses establish faster than Kentucky bluegrass, they don't tolerate the wear and tear that tall fescues can. So they work best when confined to low foot-traffic areas.
- Bentgrass (Agrostis spp., USDA zones 4 through 6), historically the grass favored on golf-course greens. Newer varieties have increased the use of bentgrass by homeowners looking for dense, cushiony, golf-greenlike turf -- or a backyard putting green. Spread by above-ground stems, known as stolons, bentgrass offers a low-growth habit, fine texture and rich-green color. Bentgrass thrives in the Northeast's cool, humid climate and fertile soil.
The best time to seed Northeast lawns is during fall, when cool-season grasses grow most vigorously and warm-season weeds are less active than they are in summer. Spring seeding also works well, but it generally requires using more seeds to obtain the same results as fall seeding.